Hypometabolism in olfactory cortical projection areas of male patients with schizophrenia: an initial positron emission tomography study

Bertollo, David N.; Cowen, Murray A.; Levy, A. V.

doi:10.1016/0165-1781(96)02619-4

Cited by 30 publications

(16 citation statements)

References 7 publications

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“…The idea that dysfunction in ventral and medial areas of PFC might be a prominent feature of SZ is supported by an increasing amount of evidence pointing to both structural (Goldstein et al 1999;Crespo-Facorro et al 2000;Pantelis et al 2003;Davatzikos et al 2005) and functional (Bertollo et al 1996;Carter et al 2001;Quintana et al 2003) abnormalities in these brain regions in schizophrenia. Behaviorally, schizophrenia patients have shown impairment on a number of tasks thought to be dependent on intact ventral PFC, including delayed alternation/object alternation (Seidman et al 1995) and the Iowa Gambling Task (IGT; Ritter et al 2004;Shurman et al 2005), although these results have not been unequivocal (see, e.g., Wilder et al 1998).…”

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confidence: 75%

Probabilistic reversal learning impairments in schizophrenia: Further evidence of orbitofrontal dysfunction

Waltz

Gold

2007

Schizophrenia Research

312

257

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Impairments in feedback processing and reinforcement learning appear to be prominent aspects of schizophrenia (SZ), which may relate to symptoms of the disorder. Evidence from cognitive neuroscience investigations indicates that disparate brain systems may underlie different kinds of feedback-driven learning. The ability to rapidly shift response tendencies in the face of negative feedback, when reinforcement contingencies are reversed, is an important type of learning thought to depend on ventral prefrontal cortex (PFC). Schizophrenia has long been associated with dysfunction in dorsolateral areas of PFC, but evidence for ventral PFC impairment in more mixed. In order to assess whether SZ patients experience particular difficulty in carrying out a cognitive function commonly linked to ventral PFC function, we administered to 34 patients and 26 controls a modified version of an established probabilistic reversal learning task from the experimental literature (Cools et al. 2002). Although SZ patients and controls performed similarly on the initial acquisition of probabilistic contingencies, patients showed substantial learning impairments when reinforcement contingencies were reversed, achieving significantly fewer reversals [Χ^2(6)=15.717, p=0.008]. Even when analyses were limited to subjects who acquired all probabilistic contingencies initially (22 patients and 20 controls), patients achieved significantly fewer reversals [Χ^2(3)=9.408, p=0.024]. These results support the idea that ventral PFC dysfunction is a prevalent aspect of schizophrenic pathophysiology, which may contribute to deficits in reinforcement learning exhibited by patients. Further studies are required to investigate the roles of dopaminergic systems in these impairments. Keywordsschizophrenia; dopamine; reinforcement; basal ganglia; prefrontal; orbitofrontal One of the most common neuropsychological findings in the schizophrenia (SZ) literature is that of impaired attentional set-shifting, as evidenced by studies using tasks like the Wisconsin Card Sort Test (WCST) and the intradimensional/extradimensional (ID/ED) attentional setshifting task. This deficit has often been linked to dysfunction of dorsolateral prefrontal cortex (DLPFC), one of the most frequently-observed neural correlates of schizophrenia (Weinberger et al. 1986;Berman et al. 1988). One possible source of set-shifting deficits in patients may be set-learning impairments related to limitations in DLPFC-dependent attentional and working memory resources. Another possible source of set-shifting difficulties, however, may be a specific impairment in reversing learned associations. The reversal of learned associations is known to depend on ventral and medial areas of prefrontal cortex (PFC) from a variety of studies involving both human and nonhuman animal subjects, including both lesion studies (Dias et al. 1996;Fellows and Farah 2003;Hornak et al. 2004) and those using physiological Corresponding Author: Dr. James Andrew Waltz, PhD, Maryland Psychiatric Research Center Pu...

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confidence: 75%

Probabilistic reversal learning impairments in schizophrenia: Further evidence of orbitofrontal dysfunction

Waltz

Gold

2007

Schizophrenia Research

312

257

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“…As such, these investigations provide impetus for the use of olfactory probes in various neuroimaging paradigms that would allow for a more detailed analysis of brain structures and processes involved in this dysfunction. For example, the majority of preliminary neuroimaging studies in patients with schizophrenia appear to support greater association of olfactory deficits with right hemisphere neurophysiologic abnormalities (Bertollo et al 1996;Clark et al 1991;Malaspina et al 1996). Expansion of this methodology with an emphasis on the use of odor stimulation tasks will doubtless advance our understanding of the olfactory dysfunction seen in this patient group.…”

Section: Discussionmentioning

confidence: 99%

“…The relationship between the olfactory measures and regional metabolism measures in this study could be confounded, however, by the fact that the stimulation task during the PET procedure was a visual continuous performance task rather than an olfactory activation task or resting baseline. Bertollo et al (1996) examined local cerebral metabolic rate within two olfactory cortical projection areas in eight healthy males and eight males with schizophrenia. Results revealed a greater degree of hypometabolism in the right lateroposterior quadrant of the orbitofrontal cortex, which receives mainly uncrossed projections from the olfactory bulbs via the pyriform and entorhinal cortex, along with a small number of olfactory and other limbic inputs from the medial subdivision of the dorsomedial thalamic nucleus.…”

Section: Functional Imaging Studiesmentioning

confidence: 99%

Olfactory Dysfunction in Schizophrenia A Qualitative and Quantitative Review

Moberg

Agrin

Gur

et al. 1999

Neuropsychopharmacology

290

183

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“…126 The literature on the Iowa Gambling Task in schizophrenia also provides evidence for impairment, [155][156][157][158][159][160][161][162] again with some exceptions. 154,[163][164][165] There is also evidence for structural and functional changes in OFC in schizophrenia, 107,[166][167][168][169] though such changes have not been directly related to reversal learning or Iowa Gambling Task performance. There is some evidence for an association between reduced OFC volume and negative symptoms.…”

Section: Value Computations and Ofc Function In Schizophreniamentioning

confidence: 99%

Goal Representations and Motivational Drive in Schizophrenia: The Role of Prefrontal-Striatal Interactions

Deanna

Dowd

2010

Schizophrenia Bulletin

426

325

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The past several years have seen a resurgence of interest in understanding the psychological and neural bases of what are often referred to as ''negative symptoms'' in schizophrenia. These aspects of schizophrenia include constructs such as asociality, avolition (a reduction in the motivation to initiate or persist in goal-directed behavior), and anhedonia (a reduction in the ability to experience pleasure). We believe that these dimensions of impairment in individuals with schizophrenia reflect difficulties using internal representations of emotional experiences, previous rewards, and motivational goals to drive current and future behavior in a way that would allow them to obtain desired outcomes, a deficit that has major clinical significance in terms of functional capacity. In this article, we review the major components of the systems that link experienced and anticipated rewards with motivated behavior that could potentially be impaired in schizophrenia. We conclude that the existing evidence suggests relatively intact hedonics in schizophrenia, but impairments in some aspects of reinforcement learning, reward prediction, and prediction error processing, consistent with an impairment in ''wanting.'' As of yet, there is only indirect evidence of impairment in anterior cingulate and orbital frontal function that may support value and effort computations. However, there are intriguing hints that individuals with schizophrenia may not be able to use reward information to modulate cognitive control and dorsolateral prefrontal cortex function, suggesting a potentially important role for cortical-striatal interactions in mediating impairment in motivated and goal-directed behavior in schizophrenia.

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Hypometabolism in olfactory cortical projection areas of male patients with schizophrenia: an initial positron emission tomography study

Cited by 30 publications

References 7 publications

Probabilistic reversal learning impairments in schizophrenia: Further evidence of orbitofrontal dysfunction

Probabilistic reversal learning impairments in schizophrenia: Further evidence of orbitofrontal dysfunction

Olfactory Dysfunction in Schizophrenia A Qualitative and Quantitative Review

Goal Representations and Motivational Drive in Schizophrenia: The Role of Prefrontal-Striatal Interactions

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